coaxial indicator

I have acquired a coaxial indicator which appears in very good condition, but, there is always a but, the dial indicator is not working. Has anyone ever managed to get the indicator out from the body. I have undone every screw I can get at but it still will not come free. If it went in it must come out, but how. Any idea other that the large hammer. The plunger guides are the problem as they are contained within the body of the tool.

Try a hair dryer, old oil goes gummy and sticks thing up. The heat loosens it enough to get some WD in there to dissolve it.

Google search for "Disassembly of Blake indicator" picks up some useful information and pictures concerning the innards of the original Blake co-axial indicator. As I understand it the imports are made in essentially the same way.

Some threads from other fora :- **LINK** , **LINK** , **LINK** .

Nice exploded parts list diagram of a Blake here :- **LINK**

The "images" section on my search throws up a good selection of pictures sowing complete and partial disassembly. I've not looked behind the pictures to see if there are links to useful text and descriptions of the process.

Hope this helps.

Clive.

With mine , I dripped naptha ( white spirits) down the top of the indicator and also on the under side of the shaft. Then tried to get it to rotate. Once I had it rotating, then I could get the plunger moving up and down. In my case , when it was free and the naptha dripped out the bottom of the spindle, I then dripped baby oil onto it. Just high grade mineral oil. Now it is fine and no issues. I see in the link Clive gave, that the use of thinned ATF. Not sure if it matter if it is mineral or synthetic, but may be worth a try. I would keep actone away from the indicator, and would stay away from WD40 and similar products as well, as suggested above and in the link from Clive. Thanks again and now I know how to take it apart if needed. The accuracy of these indicators, relies on the very close fit of the shaft to the bushes. A great and very useful piece of kit. Mine was new in about 1986 or so, certainly no newer than 1987.

I dont run mine any faster that 200 rpm, as the dial is too quick to see what is happening, depending on the bore size being indicated of course. I just wish that there was a ruby stylus available for them. Does anyone know of such a stylus? Thanks ,

Neil

+1 on the naptha. It usually cuts the gummed lubricant and lets thing work properly at5 least temporarily.

I eventually got the thing apart by dismantling the clock to find that some time in the dim and distant past, before it came into my possession some kind soul had, I suspect, given the main spindle a bit of a clump, this had damaged the pinion and rack on which the whole thing operates. I do not think it is worth trying to resurrect it, the time would be better spent on something of more use. Thanks for all the advice re de-gumming it but when I got it apart it was quite free apart from the damage to the pinion etc.

Edited By Dusty on 03/05/2018 15:44:39